Finish supply system



Jan. 23, 1968 P. CONRAD FINISH SUPPLY SYSTEM Filed Oct.

2 Sheets-Sheet l Jan. 23, 1968 P. CONRAD 3,3 5,3

FINISH SUPPLY SYSTEM Filed Oct. 1, 1964 2 Sheets-Sheet d United States Patent 3,365,326 FINESH SUPPLY SYSTEM Peter Conrad, Qharlotte, N.C., assignor to Celanese Corporation, a corporation of Delaware Filed Oct. 1, 1964, Ser. No. 400,775 13 Claims. (til. l17ltl2) This invention relates to finish supply systems, and relates more particularly to finish systems specially suitable for use in the manufacture of artificial filaments.

In the production of filamentary material, it is customary to apply a finish to the freshly formed filaments by passing these filaments into contact with the surface of a roller, one portion of which dips into a body of finish, usually contained in a finish roll pan. A plant for the production of artificial filaments generally has a great number of filament-forming stations and a correspondingly large number of finish rolls and finish roll pans, the finish being supplied to a large group of such pans from a central source, such as a head tank or pressure header, and being recirculated during use from the pans to a central sump from which the finish is returned, as by a pump, to the central source. The finish is generally supplied in the form of a dilute aqueous dispersion of the ingredients to be deposited on the filaments. Typically, these constituents comprise a lubricant such as mineral oil, which may constitute about half or more of the dispersed components, together with emulsifying and surface active agents and an antistatic agent. Generally the dispersion contains about 7095% of water. The sump is usually about 2 to 3 feet below the level of the individual pans to facilitate the return of finish to the sump by the force of gravity.

One difficulty encountered in the operation of systems of this type is the tendency for the finish lines to become clogged periodically. In the development of this invention it has been found that this difiiculty may be overcome to a large extent by the provision of means for insuring that the lines joining the finish roll pans to the sump run full regularly. I have found that in the customary method of circulating the finish, these lines which may be, for example, about 2 to 30 feet long and about /2 to 2 inches in diameter, are used only partially so that the finish tends to run on one side of each vertical return line and on the bottom of each horizontal return line; thus a large area of the liquid is exposed to the oxidizing effect of the air entrained in the lines and there is a tendency for a foam to be produced. The foaming and exposure to air result in microbial growth which in time clogs the lines. When, in accordance with this invention, the lines are kept full, this effect is greatly reduced and foaming and clogging are avoided.

To further reduce entrainment of air in the liquid, I submerge the outlets of the return lines. Thus each return line delivers its liquid below the surface of a body of the same liquid.

In the accompanying drawings which illustrate one preferred embodiment of this invention:

FIGURE 1 is a schematic view in elevation of the finish supplying system; and

FIGURE 2 is a view broken in cross-section showing the construction of the return main, level tank and levelcontrol valve.

In the drawing, reference numeral 1 designates a central finish tank, or sump, from the bottom of which the aqueous finish is pumped continuously, by pump 2, through pipe 3 to a head tank 4 located at an elevated position. From the head tank 4, the finish passes through pipe 5 and individual distribution pipes 6 and 6a to a number of finish roll pans 7 and 7a, from which it is partially removed by driven finish rolls 8 and 8a whose lower portions dip into the liquid in the finish roll pans to apply this liquid to the downwardly running yarns of freshly formed filaments 9, 9a in their passage from extrusion zones 10, Illa to windup zones 11, 11a where the yarns are wound into suitable packages, as is well known in the art. Excess finish is returned through individual return lines 12, 12a and central return line 13 to a return main 14 from which finish passes through a valve 15, more fully described below, to the finish tank 1.

At the head of return main 14, which is preferably vertical, there is a level tank 16 in which is disposed a float 17 having connected thereto a depending rod 18 at the other end of which is a movable valve member 19 (see FIG. 2). This movable valve member may be the frusto-conical tip of the rod 18, which tip is adapted to fit snugly against a correspondingly shaped valve seat 29 of the body 21 of the valve 15. To maintain the parts in alignment, there is an extension 23 at the end of the rod 18, that extension fitting in a correspondingly shaped hole 24 in the valve body 21. The rod 13 is preferably of a size such that it almost fills the return main 14, both of these elements being preferably circular in cross-section, so that when the rod is centrally aligned in said main there is only a small volume between the inner surface of the main and the outer surface of the rod for the fiow of liquid through said main.

In operation, When the level of the finish in pans 7, 7a rises above the predetermined level, the float 17 in the level tank 16 rises, opening the valve 15 and permitting liquid to flow through pipes 12, 12a and 13 and return main 14 to the tank 1. Because the rod 18 almost fills the return main 14, the flow in main i4 is quite rapid; this serves to scour the sides of the main 14 and minimizes the formation of deposits. When the level in the pans 7, 7a falls below the predetermined level, the valve 15 is closed by the action of the fioat 17. During the entire process the return lines 12, 12a, 13 and 14 remain full of liquid.

In a preferred construction the pans 7, 7a are of divided construction, each pan having a weir 25, 25a running across it so that there are in effect two compartments in each pan. The finish flows from the distribution pipes 6, 6a into the first compartments, where the finish rolls 8, 8a are situated and then over the weirs 25, 250. into the second compartments which drain into pipes 12, 12a. The float 17 and valve 15 are adjusted to maintain the level in the second compartments slightly below the heights of the weirs (e.g., about /2 to 1 inch below the tops of the weirs). Because of the fiow over the weirs an operator can easily check to see whether finish is being continuously supplied to the pans at the proper predetermined rate.

The preferred embodiment also includes means for maintaining the level in the head tank constant; means for recirculating the material from the central finish tank to the head tank and back again to keep the material in the lines agitated and prevent settling; orifices or valves in the lines to regulate the fiow rates therein; and means for deaerating the liquid flowing to the head tank.

The flow level in the head tank 4 is maintaned by the use of a fioat 26 connected to a valve 27 mounted in the central finish tank at the base of a drain pipe 28. The construction of the float 26, valve 27 and pipe 28 is preferably the same as that used in the mechanism for controlling the level in level tank 16, there being a rod 29 connected to the float 26 and passing through, and almost filling the space within, the drain pipe 28, the end of the rod being shaped to provide a valve-closing element fitting a seat in the body of the valve 27.

At the upper end of the pipe 3 there is connected a line 31, open to the atmosphere. Any air bubbles forming in line 3 can be discharged through line 31, without passing to the head tank 4. To accommodate possible overflows, the line 31 may be downwardly curved to discharge any liquid passing through line 31 into the zone directly above the liquid in head tank 4.

The flow through pipe 5 is regulated by a valve or metering orifice 30, while the fiow to the individual finish roll pans 7, 7a is metered by the use of metering orifices or valves 32, 32a in the lines 6, 6a. The fiow is generally so regulated that only a part of the finish circulated through line 5 passes to the finish roll pans and about half or more of the material flowing through line 5 by-passes these pans and is recirculated through the return line 33, and through the larger orifice or valve 34; this helps to keep the finish agitated and prevents settling or other separation. Line 33 terminates in an easily removable filter 36 which entraps lint that collects in the finish pans.

The fiow from the pump 2 is also regulated by a metering orifice 37.

It will be seen that in the system described above, all lines through which the finish passes are maintained full at all times and that, when flow takes place through such lines, it is rapid so that the walls of the lines are subjected to the securing action of the fast-moving liquid.

In the embodiment shown in the drawings, the outlets of all lines regularly delivering liquid to the central finish tank or sump 1, head tank 4, and finish roll pans 7 and 7a are situated below the liquid levels in those vessels. Thus, the level in the central finish tank 1 is maintained, by any suitable means, above the valves and 27, and the filter 36 and the outlet of line 33 are all submerged below the level of the liquid in central finish tank 1, which level is maintained in any suitable manner. Similarly the outlet of line 3 in head tank 4 is below the level maintained in that tank by the action of float 26 and valve 27 and the outlets of distribution pipes 6 and 6a are below the liquid levels set by the heights of weirs 25, a in pans 7, 7n. It will be seen that, except for a short interruption at these weirs 25, 2512 the recirculating path of the finish liquid is continuous, With no air gaps, and the entrainment of air common to the systems of the prior art does not take place. The flow in the finish roll pans and over the weirs is so gentle that foaming does not occur.

The reduction or prevention of foaming in the system of this invention gives greater latitude in the formation and use of spin finishes. Thus it makes it possible 'to use finish formulations which could not be employed previously because of their foaming tendencies, and it makes it possible to reduce or eliminate the antifoam agents in spin finish formulations.

It is advantageous to make the rods 18 and 29 of plastic material, preferably of nylon or an oxyrnethylene polymer, e.g., an oxymethylene copolymer of the type described in US. Patent No. 3,027,352. The plastic material 18 flexible; this makes it easy to remove the rods when necessary (e.g., for cleaning or replacement or resurfacing of the valve-closing portion) since the rods can be bent slightly, without permanent deformation, during the removal step.

It is to be understood that the foregoing detailed de- SCllpllOIl is given merely by way of illustration, and that variations may be made therein without departing from the spirit of this invention.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. In an apparatus for applying a liquid to a material, which includes a container, means for removing liquid from said container and for applying the removed liquid to said material, a source for supplying the liquid to the container during the applying operation, a sump for receiving excess liquid supplied to said container from said source, said sump being located below said container, and an extended pipe connecting said container to said sump, said pipe being so arranged that the liquid flows by gravity from said container to said sump through said pipe, the

improvement which comprises a valve at said sump for blocking the flow through said pipe, and control means responsive to the level of the liquid in said container for opening said valve when said level rises above a predetermined height and closing said valve when said level falls to a lower height in said container, the construction and arrangement being such that said pipe is kept full of liquid above said valve.

2. Apparatus for the production of filamentary material, comprising extrusion means for the formation of a number of strands of continuous filaments, a plurality of takeup means for winding up said strands in individual packages, a plurality of finish containers for liquid finish, a plurality of finish applicators for removing said finish from said containers and applying said finish to said strands before winding, a central finish source for the supply of liquid to said containers during the production of said strands, a sump for receiving excess liquid supplied to said containers from said source, said sump being located below said containers, and extended pipes connecting said containers to said sump, said pipes being so arranged that the liquid fiows by gravity from said container to said sump through said pipes, a valve at said sump for blocking the fiow through said pipes, and control means responsive to the level of the liquid in said containers for opening said valve when said level rises above a predetermined height and closing said valve when said level falls to a lower height in said containers, the construction and arrangement being such that said pipes are kept full of liquid above said valve.

3. Apparatus as set forth in claim 2 in which said pipes include a main pipe fed by pipes from said containers, said valve being at the foot of said main pipe, a fioat chamber at the head of said main pipe, a float in said chamber and an operative connection between said float and said valve.

4. In an apparatus for applying a liquid to a material, which includes a container, means for removing liquid from said container and for applying the removed liquid to said material, an elevated source situated above said container for applying the liquid to the container during the applying operation, a sump for receiving excess liquid supplied to said container from said source, said sump being located below said container, an extended pipe connecting said container to said sump, said pipe being so arranged that the liquid flows by gravity from said container to said sump through said pipe, a pump for returning the liquid continuously to said source from said sump, a distribution system for carrying the liquid to said containcr from said source, said distribution system having a conduit, by-passing said container, for delivering liquid from said source continuously directly to said sump, the improvement which comprises a valve at said sump for blocking the flow through said pipe, control means responsive to the level of the liquid in said container for opening said valve when said level rises above a predetermined height and closing said valve when said level falls to a lower height in said container, the construction and arrangement being such that said pipe is kept full of liquid above said valve, an excess discharge pipe leading from said source to a sump, a second valve at said sump for blocking the fiow through said excess discharge pipe, control means responsive to the level of the liquid at said source for opening said second valve when the level of the liquid at said source rises above a predetermined height and closing said valve when said source level falls to a lower height, the construction and arrangement being such that said excess discharge pipe is kept full of liquid above said second valve.

5. In an apparatus for applying a liquid to a material, which includes a container, means for removing liquid from said container and for applying the removed liquid to said material, a source for supplying the liquid to the container during the applying operation, a sump for receiving excess liquid supplied to said container from said source, said sump being located below said container,

and an extended pipe connecting said container to said sump, said pipe being so arranged that the liquid flows by gravity from said container to said sump through said pipe, the improvement which comprises a valve at said sump for blocking the flow through said pipe, and control means for opening and closing said valve in response to changes in the head of liquid in the pipe above said valve so as to keep said pipe full up to a level adjacent the level of liquid in said container.

6. In a process for the applying of a liquid to a material, in which process the liquid is supplied from a source to an application zone where the liquid is applied to said material and excess liquid is passed through an extended pipe to a sump from which it is returned to said source, the rate of flow of said excess liquid being insufficient to keep said pipe full, the improvement which comprises blocking the fiow of liquid from the foot of said pipe to said sump and periodically permitting fiow of the blocked liquid from said foot to said sump when the level of liquid in said pipe is high enough so that said pipe is maintained full.

7. In a process for applying an aqueous finish to a number of freshly spun bundles of continuous filament en route to takeup zones, in which process each bundle is passed continuously over a finish roll dipping into a bath of aqueous liquid finish, and in which process said liquid finish is supplied to a number of said baths from a central source and excess finish is passed from said baths to a central sump below said baths through a pipe, the rate of return of excess finish being insufficient to fill said pipe above said sump, the improvement which comprises periodically blocking the flow of finish from the foot of said pipe to said sump to maintain the level of the liquid in said pipe high enough so that pipe is substantially full, and periodically permitting the flow of the previously blocked liquid from the foot of said pipe to said sump to prevent said level from rising above a predetermined height, said improvement having the effect of reducing the tendency of said pipe to clog, by diminishing foaming and entrainment of air in said pipe and thereby diminishing growth of bacteria in the finish in said pipe.

8. Apparatus as set forth in claim 3 in which said float and said valve are connected by a rod extending longitudinally through, and almost filling, said main pipe.

9. Apparatus as set forth in claim 8 and including a 5 valve closure element at the end of said rod and moving with said rod.

1i). Apparatus as set forth in claim 1, in which said float and said valve are connected by a rod extending longitudinally through, and almost filling, said main pipe, there being at the valve end of said rod a valve closure element moving with said rod.

11. An apparatus as set forth in claim 1 in which said valve is submerged below the liquid level in said sump.

12. An apparatus as set forth in claim a in which said valves are submerged below the level of the liquid in said sump, said conduit has its outlet below the liquid level in said sump and there is a pipe connecting said pump to said source, said last-named pipe having its liquid outlet below the liquid level in said source.

13. In a process for applying an aqueous liquid finish to a number of freshly spun bundles of continuous filaments en route to takeup zones, in which process each bundle is passed continuously over a finish roll dipping into a bath of aqueous liquid finish, and in which process said liquid finish is supplied to a number of said baths from a body of liquid finish in a central source through a series of first pipes, in parallel, and excess liquid finish is passed from said baths to a body of liquid finish in a central sump below said baths through a second pipe while a substantial portion of the liquid finish flowing from said central source is by-passed, through a third pipe, around said baths to said body in said sump and liquid finish is delivered from said sump to said body in said source through a fourth pipe, the improvement which comprises maintaining all of said pipes full during said process and effecting the introduction of the liquid finish of each pipe into the corresponding body of liquid finish at a point below the surface of said body whereby entrainment of air and frothing of said liquid finish in its path from said baths through said sump and source is reduced.

References Cited UNITED STATES PATENTS 2,149,046 2/1939 Finnell l17-l02 X 2,649,758 8/1953 Cowgill 117-102 3,261,736 7/1966 Eilerman 3 ALFRED L. LEAVITT, Primary Examiner. J. A. BELL, Assistant Examiner. 

6. IN A PROCESS FOR THE APPLYING OF A LIQUID TO A MATERIAL, IN WHICH PROCESS THE LIQUID IS SUPPLIED FROM A SOURCE TO AN APPLICATION ZONE WHERE THE LIQUID IS APPLIED TO SAID MATERIAL AND EXCESS LIQUID, IS PASSED THROUGH AN EXTENDED PIPE TO A SUMP FROM WHICH IT IS RETURNED TO SAID SOURCE, THE RATE OF FLOW OF SAID EXCESS LIQUID BEING INSUFFICIENT TO KEEP SAID PIPE FULL, THE IMPROVEMENT WHICH COM- 